Permanent press fabric resin from crotonylidenediurea glyoxal formal dehyde aminoplast material

ABSTRACT

CROTONYLIDENEDIUREA IS REACTED WITH GLYOXAL AND THE RESULTING ADDUCT METHYLOLATED WITH FORMALDEHYDE TO PRODUCE THE CORRESPONDING TRIMETHYLOLATED DERIVATIVE WHICH EXHIBITS VERY DESIRABLE PROPERTIES AS A PERMANENT PRESS RESISN FOR FABRICS.

United States Patent PERMANENT PRESS Y FABRIC RESIN FROMCROTONYLIDENEDIUREA-GLYOXAL-FORMAL- DEHYDE AMINOPLAST MATERIAL Thomas M.Powanda, Middlesex, Lawrence B. Holzman, West Orange, and James E.Tracy, Bernardsville, N.J., assignors to Celanese Corporation, New York,N.Y. No Drawing. Filed Apr. 20, 1971, Ser. No. 135,781

Int. Cl. C07d 51/42; D06m /54, 15/58 U.S. Cl. 8115.7 7 Claims ABSTRACTOF THE DISCLOSURE Crotonylidenediurea is reacted with glyoxal and theresulting adduct rnethylolated with formaldehyde to produce thecorresponding trimethylolated derivative which exhibits very desirableproperties as a permanent press resin for fabrics.

BACKGROUND OF THE INVENTION In the last decade permanent press fabricshave been a real boon to the textile industry. The future looks evenbrighter as consumers look for permanent press properties in other thancasual wear, shirts and like apparel. It is anticipated, for instance,that use of permanent press resins in household white goods, e.g.,sheets, pillowcases and tablecloths, will account for a substantialamount of the increased demand in this decade. To meet this demand theresins must be able to impart permanent press properties withoutdegrading the fiber from which the fabric is made. Typically, the fabricis made of cellulosic materials, e.g., cotton, cotton-polyester blends,regenerated cellulosic materials, such as rayon, etc. Degradation canoccur, for example, when the resin finish is applied and cured; it mayalso occur as a result of repeated washings of the treated fabric usingthe various popular bleaches and detergents.

The concept of permanent press is twofold: crease resistance and creaseretention. Crease resistance is synonymous with wrinkle resistance andwrinkle recovery, viz., the ability of a treated fabric to resistwrinkling and to retain smoothness of shape and hand upon repeated wearand laundering. Crease retention is synonymous with durable press, viz.,the ability of a treated fabric to drip-dry without loss of crease andto be worn without ironing.

Obviously, achievement of all of these desirable properties, and others'such as resistance to soil redeposition, and the like, requireschemicals which are quite special. The objects of the present invention,therefore, are to produce and provide just such special chemicalcompositions which, when applied to fabrics as taught herein, impartthese very desirable properties.

THE INVENTION vpermanent press characteristics of the type intenselysought after by the textile industry and hereinbefore briefly described.The novel compounds of the present in- 3,764,263 Patented Oct. 9, 1973vention are prepared from crotonylidenediurea (A), also referred toherein as CDU, by reacting (A) with glyoxal to form a1,Z-hydroxyethyl-substituted crotonylidenediurea adduct B) which ismethylolated with formaldehyde to produce the correspondingtrimethylolated derivative (C), the latter being used to treat fabrics,pursuant to the present invention, to impart thereto significantpermanent press characteristics.

Reactant (A), above, viz., crotonylidenediurea, may be prepared byreacting urea with acetaldehyde in an acidic hydroxylic medium, e.g., asdescribed in U.S. Letters Patent No. 3,190,741. While it has been foundthat crotonylidenediurea suitable for use in the present invention isconveniently and preferably prepared according to the followingprocedure, it should be understood that other methods of synthesis canbe used: Thus, 270 parts of urea, parts and percentages used hereinbeing by weight unless otherwise indicated, is added to a mixture of 99parts of acetaldehyde and 600 parts of distilled water in a suitableconventional reaction vessel. The resultant solution is heated to atemperature of about C. Thirty parts of phosphoric acid (catalyst) isthen added and the temperature is thereafter maintained at between about60 C. and about C. for 1 hour during which time product crystallizes andsettles out. The reaction mixture is subsequently cooled to ambienttemperature whereupon further crystalline product crotonylidenediureasettles out. The product is separated from the supernatant liquid byfiltration, washed with water, and dried in vacuo. The yield of white,solid crotonylidenediurea (135.3 grams) is 69.9 percent of thetheoretical, based on the weight of acetaldehyde. Elemental analysis ofthe product corresponds to the formula C H O N and the infrared spectrumthereof Nujol mull) is identical to that reported in the literature (cf.Japanese Letters Patent No. 492,348) for crotonylidenediurea.

In accordance with the instant discovery, ODU readily reacts withglyoxal as follows:

(B) CD U- Glyoxal Adduct The CDU-glyoxal reaction product (adduct B) isre- 'acted, according to the present invention, with between about 2.80and about 5.0 molar proportions of formaldehyde as illustrated in theequation which follows:

EQUATION II BCDU-Glyoxal Adduct 3110110 (C) Glyoxal-HCHO The exactnature of adduct (B) in Equation 1, above, is not known but it isbelieved to be a mixture as shown in the equation; likewise,trimethylolation of the intermediate (B) of Equation 1 yields what isbelieved to be the CDU/Glyoxal/HCHO mixture (C) illustrated in EquationH.

Intermediate (B) is best prepared by reacting equimolar proportions ofglyoxal and CDU in a hydroxylic medium, preferably water, at elevatedtemperatures and atmospheric pressure. Preferably, reaction is carriedout for the most part at relatively low temperatures, e.g., in the rangeof about 40 C. to about 75 C., and then the reaction is completed byincreasing the temperature to atmospheric reflux for a relatively shortperiod of time. Usually it is best to maintain the lower temperature forless than about an hour and then bring the reaction mixture to refluxfor about 3 to about 15 minutes. Of course, these temperatures may bevaried considerably, depending upon concentrations of reactants, mediumused, and other like factors. It should be understood that, in view ofthe fact that the reaction proceeds rather readily, a wide variety oftemperatures, concentrations and pressures is permissible, the reactionconditions just mentioned being those best suited for equimolarproportions of reactants. Obviously, pressures above or belowatmospheric require higher or lower temperatures, respectively;'obviously, also, lean or excess concentrations, below or abovestoichiometric, afiect the temperature requirements for optimum results.In short, the reaction conditions are quite flexible, the stringenciesbeing imposed by desired efliciencies.

Conversion of intermediate (B) to the CDU-Glyoxal- HCO composition (C)of Equation II, above, likewise admits of a wide variety of reactionconditions. Reaction is best carried out in a hydroxylic medium, usuallywater. Generally, between about 2.80 and about 5.0 molar proportions offormaldehyde, preferably between about 2.90 and about 3.05, is usedbased on adduct (B). Typical desirable formaldethyde sources areformalin, paraformaldehyde, and the like.

Admixture of adduct (B) with, say, an aqueous solution of formaldehydegives rise to an exothermic reaction. When the reaction subsides (about40" C.), the mixture of reactants if preferably heated for up to severalhours, cooled and pH adjusted to about neutral. Broadly, a temperatureabove about 40 C. to about 105 C. is contemplated herein, the uppertemperature being, preferably, no greater than about atmospheric refluxtem perature.

cit

As in the case of the Equation I reaction described hereinbefore,reaction conditions for the Equation 11 reaction are very flexible, thestringencies also generally being dictated by desired efliciencies. Ifpressures above or below atmospheric are used, proportionately higher orlower temperatures, respectively, are usually indicated; likewise, leanor excess concentrations of formaldehyde with respect to adduct (B)could affect the temperature requirements for optimum results, as would,of course, the amount of water or other hydroxylic medium used relativeto the reactants.

Fabric treatment is carried out in a conventional pad bath in an aqueousmedium containing the resin-forming compound (C), viz., theCDU-Glyoxal-HCHO composition derived from adduct (B), and a curingcatalyst as the prinicipal ingredients. Generally, small amounts ofsurfactant and softener are present to enhance transfer of compound (C)to the fabric'being treated.

The catalyst functions to catalyze the curing process which takesbetween about 5 seconds and about 30 minutes, preferably between about 3minutes and about 15 minutes, at temperatures in the range of about 275F. to about 425 F., preferably between about 300 F. and about 350 F.Substances suitable for catalysing the curing process include anyconventional acidic catalysts or like catalysts heretofore known to beuseful in catalysing the curing of conventional aminoplast materials.Such acid catalysts are employed in conventional amounts, e.g., at aconcentration of between about 1 percent and about 50 percent by weight,based on the weight of aminoplast material. Typical catalystscontemplated herein are the water-soluble inorganic salts which behaveas so-called latent acid catalysts, e.g., ammonium chloride, magnesiumchloride, zinc nitrate, and the like.

According to a preferred mode of carrying out the fabric treatmentprocess of the present invention, the aqueous reaction mixturecontaining novel compound (C) dissolved therein is cooled to ambienttemperature, brought to a pH of about 7.0, and filtered to remove anyinsolubles which may be present. Then it is diluted with water to thedesired concentration, mixed with a conventional amount of an acidiccuring catalyst, and the fabric to be treated is immersed therein. Theamount of resin pickup by the substrate fabric is determined in largemeasure by the concentration of the resin-forming material, viz.,compound (C), in the aqueous pad bath solution. Generally, theconcentration of compound (C) in the pad bath solution (which can bedetermined gravimetrically) ranges between about 2 percent or less andabout 65 percent by weight or more, for cellulosic fabrics. Preferably,a pad bath concentration of between about 5 percent and about 45 percentis used, with a concentration of between 10 percent and about 25 percentbeing especially preferred. Percentages are based upon the total weightof the pad bath solution. The particular desired concentration ofresin-forming substance in any given instance can be convenientlyachieved by appropriate adjustment of the concentrations of reactants(i.e., CDU/glyoxal/HCHO) or by the judiciousaddition of water to aninitially relatively highly concentrated solution of resin-formingcompound (C).

After saturating the fabric with the pad bath solution, the treatedfabric is withdrawn from the bath, wrung between rollers made of aninert material (e.g., metal, ceramic, rubber, and the like), preferablyrubber rollers or adjacent, cooperatively-functioning stainless steel/rubber rollers, dried and simultaneously or subsequently heat cured at atemperature within the aforementioned range. The heat curing step can,if desired, be conducted by contacting the fabric with heated metalrollers, preferably heated stainless steel rollers.

In the present invention, the percent pickup of the CDU/Glyoxal/HCHOcomposition is measured as: percent Wet Pickup, after immersion in thepad solution;

percent Dry Pickup, after curing; percent Drypickup, after l wash;andpercent Dry Pickup, after-21-washe's.

As will be seen hereinafter, all tests arecompar'ative tests usingcommercial resins as controls and comparing theseresins with the novelcomposition (C) of the instant discovery. The tests recorded herein,o'therthan resin pickup characteristics; are intended to illustrate theeffectiveness of compound (0) with respect to wrinkle recovery, hand,deterioration of fabric, soil redeposition, and the like. Obviously,permanent press resins are not attractive if they deleteriously affectfiber strength, if wrinkle recovery is poor, etc.

Fabrics, particularly cellulosic fabrics, treated with compound (C)according to the present invention exhibit, as will be seen hereinafter,very desirable and valuable permanent press properties. The exampleswhich follow teach the novel CDU-Glyoxal adduct (B) and the novelCDU/Glyoxal/HCHO composition (C) of the instant discovery and processesfor preparing same. In addition, treatment of fabrics with resin-formingcompound (C) is fully disclosed, as well as a number of tests comparingthe latters efficacy with that of the following commercially popularresin-forming compounds:

O CHaOH HOILC-N N-CHzOH RO- N H H CHzOH H H [R hydroxyalkyl or alkyl]PERMAFRESHHlBB AEROTEX"82 (dimethyloidihydroxyethyleneurea) (carbamate)DMDHEU Trademark for permanent press compound sold by Sun Chemical Co.,Wood River Junction, R.I.

"Trademark for permanent press compound sold by American Cyanamid Co.,Bound Brook, NJ.

The followingexamples are merely intended to be illustrative of certainof the preferred embodiments within the spirit and scope of the presentinvention and, therefore, are not to be interpreted too restrictively;parts and percentages given in the examples are by weight, unlessotherwise indicated;

Example I To a reaction vessel is fed 468 grams of crotonylidenediurea,395 grams of 40% glyoxal aqueous solution and water, thus providing aCDU/Glyoxal molar ratio of 1:1. Sufiicient water is introduced to obtaingood stirring (approximately 165 grams). .The mixture of reactants isheated to 60 C., held at that temperature for 45 minutes, and thenslowly heated to atmospheric reflux (103 C.) and held atthat'temperature for 5 minutes before cooling the reaction mixture toambient temperature and then filtering to remove unreacted CDU (128grams)..

The filtrate (1055 grams) therefore contains 340 grams (approximately 2moles) of reacted CDU, i.e., the CDU/ Glyoxal adduct (B),describedhereinabove in Equation I,

in solution.

Example II aforementioned commercial aminoplast materials as follows:

The product CDU/Glyoxal/HCHO composition (C) of Example II, above, isused to treat plain weave white 50/50 cotton-polyester (PE) cloth, ofthe type used in shirts or household goods (e.g., sheets andpillowcases). The test procedure is as follows:

Tr1ton X-lOO is a trademark for an alkylaryl polyether alcoholsurfactant sold by Rohm & Haas Co., Philadelphia, Pa.

2 Lubriton KN is a trademark for a softener comprised of a nonlonicemulsion of a high density of olefin sold by Chas. S. Tanner Co.,Warwick, RI.

CatalystKR is a magnesium chloride-based catalyst solution sold by SunChemical 00., Wood River Junction, R.I.

Procedure Standard pad bath 70-80% wet pickup Dry at 220 F. for 2minutes Cure at 325 F. for 12 minutes 79% dry pickup After wash Half ofthe test swatches are laundered through 20 cycles.

Tests Wrinkle recovery Stiffness Tearing strength Abrasion resistance(ASTM D-l-64T) The following table shows the pickup properties of eachof the controls as compared with compound (C), the product of ExampleII, above:

TABLE II.-RESIN ADD-ON Percent d.r ieku Percent Percent after p e W drpickup pickup 1 wash 21 washes Aerotex s2. 7s 7. 0 Permalnesh 113B 788.7 CD U/glyoxal/HCHO 77. 7 8. 9 3. 6 1. 7

Wrinkle recovery characteristics of the fabric of ExampleHI, above,treated with the compounds of Table 11 is determined by a well-knownmethod: ASTM D-1295- 67-Warp direction only. The results of these testsfollow:

TABLE IIL-WRINKLE RECOVERY Recovery in degrees Cantilever stiffness ofthe fabric of Example IH using the compounds of Table H is determinedusing the meth- 7 d: ASTM D-1388-64-Warp direction only. Theresults areas follows: TABLE 1V.CANTILEVER STIFFNESS Tearing strength of the fabricof Example III, above, using the compounds of Table II is determined bythe method: ASTM D-2261-64T-Warp direction only. The results are asfollows:

TABLE V.TEARING STRENGTH BY THE TONGUE (SINGLE RIP) METHOD Break load(in pounds) After 20 Initial wash cycles Blank (untreated 50/50PEzcotton) 3. 14 4. 08 Controls:

Aerotex 82 3. 62 3. 69 Permairesh 113B 3. 75 4. 13 CD U/glyoxal/HCHO 3.02 2. 97

Conventional soil redeposition tests showed the product of Example 11,i.e., compound (C), to be superior to Permafresh 113B (DMDHEU). Using asmall amount of anti-soil-redeposition agent for polyester/cotton blendswhen subjecting the fabric of Example III, treated as taught in the sameexample, to an otherwise conventional soil redeposition test showed thefabric treated with CDU/ Glyoxal/HCHO compound (C) performed as well asthe Aerotex 82 treated fabric and better than the Permafresh113B-treated fabric under the same conditions. In other words, theAerotex 82-treated fabric and the compound (C)-treated fabric bothremained almost completely white. The anti-soil-redeposition agent usedis a water-soluble methyl cellulose derivative (4000 cps.) bearing thetrademark METHOCEL-90HG and sold by Dow Chemical Corp, Midland, Mich. Aconcentration of 1%, by weight, of Methocel-HG is added to theconventional soil redeposition test soiling bath alluded to hereinabove;the concentration, viz, 1% by weight, is based on the total weight ofthe soil bath. The use of methyl cellulose derivatives (Methocel) isclaimed in copending application Ser. No. 22,140 filed Apr. 2, 1970, byA. S. Forschirm et al. entitled Anti-Soiling Polyester Textile Material,now Patent No. 3,668,000.

As is evident from Tables III and IV, above, the wrinkle recovery andstillness performance of compound (C) compares very favorably with theperformance of the commercial resins, even after multiple launderings.This indicates, in the case of wrinkle recovery, good bonding of thecompound (C) resin to the fabric. Tear strength data reported in TableV, above, showed compound (C), like the commercial controls, produced nosignificant deterioration in fiber strength. Abrasion resistance tests(ASTM D-1175-64T) not tabulated hereinabove, likewise indicated nosignificant deterioration in fiber strength.

Pursuant to statutory requirements, there are described above theinvention and what are now considered its best embodimentslt shouldbeunderstood, however, that the invention can be practicedotherwise thanas specifically described, within the scope of the appended claims.

Whatis claimed is:

A proces's fortreati'ng fabric to impartpermanent press propertiesthereto which comprises contacting the fabric with an acidiccuringcatalyst and an aqueous sold,-

tion of a methylolated compound prepared "by reacting a crotonylidcnediurea-glyoxal adduct having the formula H OH with formaldehydeand subjecting the thustreated fabric to elevate temperatures sufiicientto cure said compound to a resin consistency providing permanent pressproperties to the fabric.

2. The process of claim 1 wherein-the fabric is a cellu losic fabric.

3. The process of claim 2 wherein the fabric is a poly ester/cottonblend.

4. The process of claim 3 wherein the acidic curing catalyst is selectedfrom the group consisting of water-soluble inorganic salts whichbehave-as latent acid catalysts.

5. The process of claim 4 wherein the curing catalyst is magnesiumchloride.

6. The process of claim 5 wherein the curing temperature is in the rangeof about 275 F. to about 425 F.-

7. The process of claim 6 wherein said'methylolated compound is presentin thetreating solution in a concentration between about 2percent andabout percent by weight. i

References Cited Schroeder 260-256.4 C

GEORGE F. LESMES, Primary Eiraminer I. CANNON, Assistant Examiner8-115.6, 182, 186, 189, Dig; 260 -2564 C, 69 R, 256.4

